Young mother here, I'm asking experienced mothers for advice. My baby …

Young mother here, I'm asking experienced mothers for advice. My baby hasn't pooped in two days but he often burps. His tummy is soft. He sleeps well for 2-3 hours but I'm worried if that's normal? I breastfeed but sometimes give him formula around 40-50 grams at night to help him sleep better. He cries when hungry and then falls asleep after eating again.